https://en.wikipedia.org/wiki/Gravity_Probe_B Gravity Probe B From Wikipedia, the free encyclopedia Jump to navigation Jump to search Orbital gravitational observatory Gravity Probe B Artist concept of Gravity Probe B.jpg Mission type Astrophysics Operator NASA/Stanford University COSPAR ID 2004-014A Edit this at Wikidata SATCAT no. 28230 Website einstein.stanford.edu Mission duration 17.5 months^[1] Spacecraft properties Manufacturer Lockheed Martin Launch mass 3,100 kg (6,800 lb)^[1] Dimensions 6.4 m x 2.6 m (21.0 ft x 8.5 ft)^[1] 606 W Power Spacecraft: 293 W Payload: 313 W^[1] Start of mission Launch date 20 April 2004, 16:57:24 (2004-04-20UTC16:57:24Z) UTC Rocket Delta II 7920-10C Launch site Vandenberg SLC-2W End of mission Disposal Decommissioned Deactivated 8 December 2010 (2010-12-09) Orbital parameters Reference system Geocentric Regime Low Earth Semi-major axis 7,027.4 km (4,366.6 mi) Eccentricity 0.0014^[1] Perigee altitude 641 km (398 mi)^[2] Apogee altitude 645 km (401 mi)^[2] Inclination 90.007o^[1] Period 97.65 minutes^[3] Epoch 2004-04-20 15:57:00 UTC^[2] Gravity Probe B (GP-B) was a satellite-based experiment to test two unverified predictions of general relativity: the geodetic effect and frame-dragging. This was to be accomplished by measuring, very precisely, tiny changes in the direction of spin of four gyroscopes contained in an Earth-orbiting satellite at 650 km (400 mi) altitude, crossing directly over the poles. The satellite was launched on 20 April 2004 on a Delta II rocket.^[4] The spaceflight phase lasted until 2005;^[5] Its aim was to measure spacetime curvature near Earth, and thereby the stress-energy tensor (which is related to the distribution and the motion of matter in space) in and near Earth. This provided a test of general relativity, gravitomagnetism and related models. The principal investigator was Francis Everitt. Initial results confirmed the expected geodetic effect to an accuracy of about 1%. The expected frame-dragging effect was similar in magnitude to the current noise level (the noise being dominated by initially unmodeled effects due to nonuniform coatings on the gyroscopes). Work continued to model and account for these sources of error, thus permitting extraction of the frame-dragging signal. By August 2008, the frame-dragging effect had been confirmed to within 15% of the expected result,^[6] and the December 2008 NASA report indicated that the geodetic effect was confirmed to be better than 0.5%.^[7] In an article published in the journal Physical Review Letters in 2011, the authors reported analysis of the data from all four gyroscopes results in a geodetic drift rate of -6601.8+-18.3 mas/yr and a frame-dragging drift rate of -37.2+-7.2 mas/yr, in good agreement with the general relativity predictions of -6606.1+- 0.28% mas/yr and -39.2+-0.19% mas/yr, respectively.^[8] [ ] Contents * 1 Overview * 2 Experimental setup * 3 History * 4 Mission timeline + 4.1 NASA review + 4.2 Data analysis after NASA * 5 See also * 6 References * 7 External links Overview[edit] [220px-Gravity_Probe_B] Gravity Probe B with solar panels folded. Gravity Probe B was a relativity gyroscope experiment funded by NASA. Efforts were led by the Stanford University physics department with Lockheed Martin as the primary subcontractor. Mission scientists viewed it as the second relativity experiment in space, following the successful launch of Gravity Probe A (GP-A) in 1976. The mission plans were to test two unverified predictions of general relativity: the geodetic effect and frame-dragging. This was to be accomplished by measuring, very precisely, tiny changes in the direction of spin of four gyroscopes contained in an Earth satellite orbiting at 650 km (400 mi) altitude, crossing directly over the poles. The gyroscopes were intended to be so free from disturbance that they would provide a near-perfect spacetime reference system. This would allow them to reveal how space and time are "warped" by the presence of the Earth, and by how much the Earth's rotation "drags" space-time around with it. The geodetic effect is an effect caused by space-time being "curved" by the mass of the Earth. A gyroscope's axis when parallel transported around the Earth in one complete revolution does not end up pointing in exactly the same direction as before. The angle "missing" may be thought of as the amount the gyroscope "leans over" into the slope of the space-time curvature. A more precise explanation for the space curvature part of the geodetic precession is obtained by using a nearly flat cone to model the space curvature of the Earth's gravitational field. Such a cone is made by cutting out a thin "pie-slice" from a circle and gluing the cut edges together. The spatial geodetic precession is a measure of the missing "pie-slice" angle. Gravity Probe B was expected to measure this effect to an accuracy of one part in 10,000, the most stringent check on general relativistic predictions to date. The much smaller frame-dragging effect is an example of gravitomagnetism. It is an analog of magnetism in classical electrodynamics, but caused by rotating masses rather than rotating electric charges. Previously, only two analyses of the laser-ranging data obtained by the two LAGEOS satellites, published in 1997 and 2004, claimed to have found the frame-dragging effect with an accuracy of about 20% and 10% respectively,^[9]^[10]^[11] whereas Gravity Probe B aimed to measure the frame dragging effect to a precision of 1%.^[12] However, Lorenzo Iorio claimed that the level of total uncertainty of the tests conducted with the two LAGEOS satellites has likely been greatly underestimated.^[13]^[14]^[15]^ [16]^[17]^[18] A recent analysis of Mars Global Surveyor data has claimed to have confirmed the frame dragging effect to a precision of 0.5%,^[19] although the accuracy of this claim is disputed.^[20]^[21] Also the Lense-Thirring effect of the Sun has been recently investigated in view of a possible detection with the inner planets in the near future.^[22]^[23] The launch was planned for 19 April 2004 at Vandenberg Air Force Base but was scrubbed within 5 minutes of the scheduled launch window due to changing winds in the upper atmosphere. An unusual feature of the mission is that it only had a one-second launch window due to the precise orbit required by the experiment. On 20 April, at 9:57:23 AM PDT (16:57:23 UTC) the spacecraft was launched successfully. The satellite was placed in orbit at 11:12:33 AM (18:12:33 UTC) after a cruise period over the south pole and a short second burn. The mission lasted 16 months. Some preliminary results were presented at a special session during the American Physical Society meeting in April 2007. NASA initially requested a proposal for extending the GP-B data analysis phase through December 2007. The data analysis phase was further extended to September 2008 using funding from Richard Fairbank, Stanford and NASA, and beyond that point using non-NASA funding only.^[6] Final science results were reported in 2011. Experimental setup[edit] [220px-Einstein_gyro_gravity_pr] At the time, the fused quartz gyroscopes created for Gravity Probe B were the most nearly perfect spheres ever created by humans.^[24] The gyroscopes differ from a perfect sphere by no more than 40 atoms of thickness. One is pictured here refracting the image of Albert Einstein in background. Gravity Probe B Confirms the Existence of Gravitomagnetism.jpg The Gravity Probe B experiment comprised four London moment gyroscopes and a reference telescope sighted on IM Pegasi, a binary star in the constellation Pegasus. In polar orbit, with the gyro spin directions also pointing toward IM Pegasi, the frame-dragging and geodetic effects came out at right angles, each gyroscope measuring both. The gyroscopes were housed in a dewar of superfluid helium, maintaining a temperature of under 2 kelvins (-271 degC; -456 degF). Near-absolute zero temperatures were required to minimize molecular interference, and enable the lead and niobium components of the gyroscope mechanisms to become superconductive. At the time of their manufacture, the gyroscopes were the most nearly spherical objects ever made (two gyroscopes still hold that record, but third place has been taken by the silicon spheres made by the Avogadro project). Approximately the size of ping pong balls, they were perfectly round to within forty atoms (less than 10 nm). If one of these spheres were scaled to the size of the Earth, the tallest mountains and deepest ocean trench would measure only 2.4 m (8 ft) high.^[25] The spheres were made of fused quartz and coated with an extremely thin layer of niobium. A primary concern was minimizing any influence on their spin, so the gyroscopes could never touch their containing compartment. They were held suspended with electric fields, spun up using a flow of helium gas, and their spin axes were sensed by monitoring the magnetic field of the superconductive niobium layer with SQUIDs. (A spinning superconductor generates a magnetic field precisely aligned with the rotation axis; see London moment.) IM Pegasi was chosen as the guide star for multiple reasons. First, it needed to be bright enough to be usable for sightings. Then it was close to the ideal positions near the celestial equator. Also important was its well-understood motion in the sky, which was helped by the fact that this star emits relatively strong radio signals. In preparation for the setup of this mission, astronomers analyzed the radio-based position measurements with respect to far distant quasars taken over several years to understand its motion as precisely as needed. History[edit] [220px-Gravity_Probe_turning_ax] A representation of the geodetic effect. The conceptual design for this mission was first proposed by an MIT professor, George Pugh, who was working with the U.S. Department of Defense in 1959 and later discussed by Leonard Schiff (Stanford) in 1960 at Pugh's suggestion, based partly on a theoretical paper about detecting frame dragging that Schiff had written in 1957. It was proposed to NASA in 1961, and they supported the project with funds in 1964. This grant ended in 1977 after a long phase of engineering research into the basic requirements and tools for the satellite. In 1986 NASA changed plans for the Space Shuttle, which forced the mission team to switch from a shuttle-based launch design to one that was based on the Delta 2, and in 1995 tests planned of a prototype on a shuttle flight were cancelled as well. Gravity Probe B marks the first time that Stanford University has been in control of the development and operations of a space satellite funded by NASA. The total cost of the project was about $750 million.^[26] Mission timeline[edit] Main article: Gravity Probe B mission timeline This is a list of major events for the GP-B experiment. 20 April 2004 Launch of GP-B from Vandenberg AFB and successful insertion into polar orbit. 27 August 2004 GP-B entered its science phase. On mission day 129 all systems were configured to be ready for data collection, with the only exception being gyro 4, which needed further spin axis alignment. 15 August 2005 The science phase of the mission ended and the spacecraft instruments transitioned to the final calibration mode. 26 September 2005 The calibration phase ended with liquid helium still in the dewar. The spacecraft was returned to science mode pending the depletion of liquid helium. February 2006 Phase I of data analysis complete September 2006 Analysis team realised that more error analysis was necessary (particularly around the polhode motion of the gyros) than could be done in the time to April 2007 and applied to NASA for an extension of funding to the end of 2007. December 2006 Completion of Phase III of data analysis 14 April 2007 Announcement of best results obtained to date. Francis Everitt gave a plenary talk at the meeting of the American Physical Society announcing initial results:^[27] "The data from the GP-B gyroscopes clearly confirm Einstein's predicted geodetic effect to a precision of better than 1 percent. However, the frame-dragging effect is 170 times smaller than the geodetic effect, and Stanford scientists are still extracting its signature from the spacecraft data."^[28] 8 December 2010 GP-B spacecraft decommissioned, left in its 642 km (399 mi) polar orbit.^[29] 4 May 2011 GP-B Final experimental results were announced. In a public press and media event at NASA Headquarters, GP-B Principal Investigator, Francis Everitt presented the final results of Gravity Probe B.^[30] 19 November 2015 Publication of GP-B Special Volume (Volume #32, Issue #22) in the peer-reviewed journal, Classical and Quantum Gravity.^[31] On 9 February 2007, it was announced that a number of unexpected signals had been received and that these would need to be separated out before final results could be released. In April it was announced that the spin axes of the gyroscopes were affected by torque, in a manner that varied over time, requiring further analysis to allow the results to be corrected for this source of error. Consequently, the date for the final release of data was pushed back several times. In the data for the frame-dragging results presented at the April 2007 meeting of the American Physical Society, the random errors were much larger than the theoretical expected value and scattered on both the positive and negative sides of a null result, therefore causing skepticism as to whether any useful data could be extracted in the future to test this effect. In June 2007, a detailed update was released explaining the cause of the problem, and the solution that was being worked on. Although electrostatic patches caused by non-uniform coating of the spheres were anticipated, and were thought to have been controlled for before the experiment, it was subsequently found that the final layer of the coating on the spheres defined two-halves of slightly different contact potential, which gave the sphere an electrostatic axis. This created a classical dipole torque on each rotor, of a magnitude similar to the expected frame dragging effect. In addition, it dissipated energy from the polhode motion by inducing currents in the housing electrodes, causing the motion to change with time. This meant that a simple time-average polhode model was insufficient, and a detailed orbit by orbit model was needed to remove the effect. As it was anticipated that "anything could go wrong", the final part of the flight mission was calibration, where amongst other activities, data was gathered with the spacecraft axis deliberately misaligned for 24 hours, to exacerbate any potential problems. This data proved invaluable for identifying the effects. With the electrostatic torque modeled as a function of axis misalignment, and the polhode motion modeled at a sufficiently fine level, it was hoped to isolate the relativity torques to the originally expected resolution. Stanford agreed to release the raw data to the public at an unspecified date in the future. It is likely that this data will be examined by independent scientists and independently reported to the public well after the final release by the project scientists. Because future interpretations of the data by scientists outside GP-B may differ from the official results, it may take several more years for all of the data received by GP-B to be completely understood.^[ needs update] NASA review[edit] A review by a panel of 15 experts commissioned by NASA recommended against extending the data analysis phase beyond 2008. They warned that the required reduction in noise level (due to classical torques and breaks in data collection due to solar flares) "is so large that any effect ultimately detected by this experiment will have to overcome considerable (and in our opinion, well justified) skepticism in the scientific community".^[32] Data analysis after NASA[edit] NASA funding and sponsorship of the program ended on 30 September 2008, but GP-B secured alternative funding from King Abdulaziz City for Science and Technology in Saudi Arabia^[6] that enabled the science team to continue working at least through December 2009. On 29 August 2008, the 18th meeting of the external GP-B Science Advisory Committee was held at Stanford to report progress. The ensuing SAC report to NASA states: The progress reported at SAC-18 was truly extraordinary and we commend the GPB team for this achievement. This has been a heroic effort, and has brought the experiment from what seemed like a state of potential failure, to a position where the SAC now believes that they will obtain a credible test of relativity, even if the accuracy does not meet the original goal. In the opinion of the SAC Chair, this rescue warrants comparison with the mission to correct the flawed optics of the Hubble Space Telescope, only here at a minuscule fraction of the cost. -- SAC #18 Report to NASA The Stanford-based analysis group and NASA announced on 4 May 2011 that the data from GP-B indeed confirms the two predictions of Albert Einstein's general theory of relativity.^[33] The findings were published in the journal Physical Review Letters.^[8] The prospects for further experimental measurement of frame-dragging after GP-B were commented on in the journal Europhysics Letters.^[34] See also[edit] * #Spaceflight portal * Frame-dragging * Gravity Probe A * Gravitomagnetism * Modified Newtonian dynamics * Tests of general relativity * Timeline of gravitational physics and relativity References[edit] 1. ^ ^a ^b ^c ^d ^e ^f "Gravity Probe B" (PDF). NASA Facts. NASA and Stanford University. February 2005. Retrieved 17 March 2011. 2. ^ ^a ^b ^c "Spacecraft orbit: Gravity Probe B". National Space Science Data Center. 2004. Retrieved 18 January 2015. 3. ^ G. Hanuschak; H. Small; D. DeBra; K. Galal; A. Ndili; P. Shestople. "Gravity Probe B GPS Orbit Determination with Verification by Satellite Laser Ranging" (PDF). Retrieved 17 March 2011. 4. ^ "Frequently asked Questions". Gravity Probe B. Stanford University. Answers to Spacecraft and Mission Operations Questions: 1. When and where was GP-B launched, and where can I find photos, video or news clips of the launch?. Retrieved 14 May 2009. 5. ^ "Frequently asked Questions". Gravity Probe B. Stanford University. Answers to Spacecraft and Mission Operations Questions: 4. Where is the GP-B Mission Operations Center (MOC) for controlling the spacecraft in orbit?. Retrieved 14 May 2009. 6. ^ ^a ^b ^c Gugliotta, G. (16 February 2009). "Perseverance Is Paying Off for a Test of Relativity in Space". The New York Times . Retrieved 18 February 2009. 7. ^ Everitt, C.W.F.; Parkinson, B.W. (2009). "Gravity Probe B Science Results--NASA Final Report" (PDF). Retrieved 2 May 2009. 8. ^ ^a ^b Everitt; et al. (2011). "Gravity Probe B: Final Results of a Space Experiment to Test General Relativity". Physical Review Letters. 106 (22): 221101. arXiv:1105.3456. Bibcode: 2011PhRvL.106v1101E. doi:10.1103/PhysRevLett.106.221101. PMID 21702590. S2CID 11878715. 9. ^ Ciufolini, I.; Lucchesi, D.; Vespe, F.; Chieppa, F. (1997). "Detection of Lense-Thirring Effect Due to Earth's Spin". arXiv: gr-qc/9704065. 10. ^ "Einstein's warp effect measured". BBC News. 21 October 2004. Retrieved 14 May 2009. 11. ^ Peplow, M. (2004). "Spinning Earth twists space". Nature News. doi:10.1038/news041018-11. 12. ^ "Overview of the GP-B Mission". Gravity Probe B. Stanford University. 2011. Retrieved 18 January 2015. 13. ^ Iorio, L. (2005). "On the reliability of the so far performed tests for measuring the Lense-Thirring effect with the LAGEOS satellites". New Astronomy. 10 (8): 603-615. arXiv:gr-qc/0411024. Bibcode:2005NewA...10..603I. doi:10.1016/j.newast.2005.01.001. S2CID 14563677. 14. ^ Iorio, L. (2006). "A critical analysis of a recent test of the Lense-Thirring effect with the LAGEOS satellites". Journal of Geodesy. 80 (3): 123-136. arXiv:gr-qc/0412057. Bibcode: 2006JGeod..80..128I. doi:10.1007/s00190-006-0058-4. S2CID 2157036 . 15. ^ Iorio, L. (2007). "An assessment of the measurement of the Lense-Thirring effect in the Earth gravity field, in reply to: "On the measurement of the Lense-Thirring effect using the nodes of the LAGEOS satellites, in reply to "On the reliability of the so far performed tests for measuring the Lense-Thirring effect with the LAGEOS satellites" by L. Iorio," by I. Ciufolini and E. Pavlis". Planetary and Space Science. 55 (4): 503-511. arXiv: gr-qc/0608119. Bibcode:2007P&SS...55..503I. doi:10.1016/ j.pss.2006.08.001. 16. ^ Iorio, L. (February 2010). "Conservative evaluation of the uncertainty in the LAGEOS-LAGEOS II Lense-Thirring test". Central European Journal of Physics. 8 (1): 25-32. arXiv:0710.1022. Bibcode:2010CEJPh...8...25I. doi:10.2478/s11534-009-0060-6. S2CID 16668743. 17. ^ Iorio, L. (December 2009). "An Assessment of the Systematic Uncertainty in Present and Future Tests of the Lense-Thirring Effect with Satellite Laser Ranging". Space Science Reviews. 148 (1-4): 363-381. arXiv:0809.1373. Bibcode:2009SSRv..148..363I. doi :10.1007/s11214-008-9478-1. S2CID 15698399. 18. ^ Iorio, L. (2009). Recent Attempts to Measure the General Relativistic Lense-Thirring Effect with Natural and Artificial Bodies in the Solar System. Vol. 017. Proceedings of Science PoS (ISFTG). arXiv:0905.0300. Bibcode:2009ftg..confE...1I. 19. ^ Iorio, L. (August 2006). "A note on the evidence of the gravitomagnetic field of Mars". Classical and Quantum Gravity. 23 (17): 5451-5454. arXiv:gr-qc/0606092. Bibcode:2006CQGra..23.5451I . doi:10.1088/0264-9381/23/17/N01. S2CID 118233440. 20. ^ Krogh, K. (November 2007). "Comment on 'Evidence of the gravitomagnetic field of Mars'". Classical and Quantum Gravity. 24 (22): 5709-5715. arXiv:astro-ph/0701653. Bibcode: 2007CQGra..24.5709K. doi:10.1088/0264-9381/24/22/N01. S2CID 12238950. 21. ^ Iorio, L. (June 2010). "On the Lense-Thirring test with the Mars Global Surveyor in the gravitational field of Mars". Central European Journal of Physics. 8 (3): 509-513. arXiv:gr-qc/0701146. Bibcode:2010CEJPh...8..509I. doi:10.2478/s11534-009-0117-6. S2CID 16052420. 22. ^ Iorio, L. (2005). "Is it possible to measure the Lense-Thirring effect on the orbits of the planets in the gravitational field of the Sun?". Astronomy and Astrophysics. 431: 385-389. arXiv:gr-qc/ 0407047. Bibcode:2005A&A...431..385I. doi:10.1051/ 0004-6361:20041646. S2CID 10865318. 23. ^ Iorio, L. (2008). "Advances in the Measurement of the Lense-Thirring Effect with Planetary Motions in the Field of the Sun". Scholarly Research Exchange. 2008: 5235. arXiv:0807.0435. Bibcode:2008ScReE2008.5235I. doi:10.3814/2008/105235. S2CID 6254966. 24. ^ Barry, P.L. (26 April 2004). "A Pocket of Near-Perfection". Science@NASA. Archived from the original on 12 May 2009. Retrieved 20 May 2009. 25. ^ Hardwood, W. (20 April 2004). "Spacecraft launched to test Albert Einstein's theories". Spaceflight Now. Retrieved 14 May 2009. 26. ^ Devin Powell (4 May 2011). "Gravity Probe B finally pays off". Science News. 27. ^ "Exciting April Plenary Talks - Saturday, 14 April". Archived from the original on 20 February 2007. Retrieved 16 November 2006 . 28. ^ Khan, B. (14 April 2007). "Was Einstein Right" (PDF). Stanford News. Stanford University. Retrieved 14 May 2009. 29. ^ "Gravity Probe-B Latest News". NASA. Retrieved 20 February 2011 . 30. ^ "GP-B STATUS UPDATE -- May 4, 2011". Gravity Probe B. NASA and Stanford University. NASA Headquarters Science Update/Press Conference. Retrieved 6 May 2011. 31. ^ Clifford M Will (17 November 2015). "Focus issue: Gravity Probe B". Classical and Quantum Gravity. IOP. 32 (22): 220301. Bibcode: 2015CQGra..32v0301W. doi:10.1088/0264-9381/32/22/220301. 32. ^ Hecht, J. (20 May 2008). "Gravity Probe B scores 'F' in NASA review". New Scientist. Retrieved 20 May 2008. 33. ^ "Stanford's Gravity Probe B confirms two Einstein theories". Stanford News. Stanford University. 4 May 2011. 34. ^ L. Iorio (November 2011). "Some considerations on the present-day results for the detection of frame-dragging after the final outcome of GP-B". Europhysics Letters. 96 (3): 30001. arXiv :1105.4145. Bibcode:2011EL.....9630001I. doi:10.1209/0295-5075/96 /30001. S2CID 118532421. External links[edit] # Wikimedia Commons has media related to Gravity Probe B. * Gravity Probe B web site at NASA * Gravity Probe B Web site at Stanford * Graphic explanation of how Gravity Probe B works * NASA GP-B launch site * NASA article on the technologies used in Gravity Probe B * Frame Dragging at the Wayback Machine (archived 22 September 2009) * General Relativistic Frame Dragging * Layman's article on the project progress * IOP Classical and Quantum Gravity, Volume #32, Issue #22, Special Focus Issue on Gravity Probe B * Gravity Probe B Collection, The University of Alabama in Huntsville Archives and Special Collections * v * t * e - 2003 * Orbital launches in 2004 * 2005 - Estrela do Sul 1 | Progress M1-11 | AMC-10 | USA-176 | Molniya-1 No.93 | Rosetta (Philae) | MBSat | Eutelsat W3A | USA-177 | Globus No.17L | Superbird-A2 | Tansuo 1 * Naxing 1 | Soyuz TMA-4 | Gravity Probe B | Ekspress AM-11 | DirecTV-7S | AMC-11 | Formosat-2 | Progress M-49 | Kosmos 2405 | Kosmos 2406 | Intelsat 10-02 | USA-178 | Telstar 18 | Demeter * AprizeSat-1 * AprizeSat-2 * Saudisat-2 * SaudiComsat-1 * SaudiComsat-2 * UniSat-3 * AMSAT-Echo | Aura | Anik F2 | Kosmos 2407 | Tan Ce 2 | MESSENGER | Amazonas 1 | Progress M-50 | FSW-19 | USA-179 | Ofek-6 | Shijian 6A * Shijian 6B | GSAT-3 / EDUSAT | Kosmos 2408 * Kosmos 2409 | Kosmos 2410 | FSW-20 | Soyuz TMA-5 | AMC-15 | Feng Yun 2C | Ekspress AM-1 | Zi Yuan 2C | USA-180 | Tansuo 2 | Swift | AMC-16 | Helios IIA * Nanosat 01 * Essaim 1 * Essaim 2 * Essaim 3 * Essaim 4 * Parasol | HLVOLSDP * Sparkie * Ralphie | Progress M-51 | Sich-1M * MK-1TS | Kosmos 2411 * Kosmos 2412 * Kosmos 2413 Payloads are separated by bullets ( * ), launches by pipes ( | ). 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