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The Gravity Recovery and Interior Laboratory (GRAIL), a NASA Discovery mission, twin spacecraft were launched on 10 September 2012 and were inserted into lunar orbit on 31 December 2011 and 01 January 20121. The objective of the mission was to measure a high-resolution lunar gravity field using inter-spacecraft range measurements in order to investigate the interior structure of the Moon from crust...
Radio Science (RS) experiments currently rely on unmodulated CW RF signal carrier for spectral purity and maximized signal-to-noise ratio. This requires missions to carefully schedule them away from periods of high rate telemetry. In the era of optical communications, current systems experience the same problem. In this paper, we derive a data processing architecture that will yield high-accuracy...
The Gravity Recovery and Interior Laboratory (GRAIL) mission successfully ended in December, 2012 after an extended science phase of over 280 days mapping the gravitation field gradient of the Moon with a precision of better than 50 E-6 g's over the entire lunar surface. The mission was performed by two tandem flying spacecraft, both of which carried a Microwave Dual One-way Ranging (DOWR) instrument...
Radio Science started when it became apparent with early deep space missions that occultations by planetary atmospheres would affect the quality of radio communications. Since then the atmospheric properties and other aspects of planetary science, solar science, and fundamental physics were studied by scientists. Radio Science data was always extracted from a received pure residual carrier (without...
During the Entry, Descent, and Landing (EDL) of NASA's Mars Science Laboratory (MSL), or Curiosity, rover to Gale Crater on Mars on August 6, 2012 UTC, the rover transmitted an X-band signal composed of carrier and tone frequencies and a UHF signal modulated with an 8kbps data stream. During EDL, the spacecraft's orientation is determined by its guidance and mechanical subsystems to ensure that the...
Mars Science Laboratory (MSL) undergoes extreme heating and acceleration during Entry, Descent, and Landing (EDL) on Mars. Unknown dynamics lead to large Doppler shifts, making communication challenging. During EDL, a special form of Multiple Frequency Shift Keying (MFSK) communication is used for Direct-To-Earth (DTE) communication. The X-band signal is received by the Deep Space Network (DSN) at...
NASA is currently developing the capability to deploy deep space optical communications links. This creates the opportunity to utilize the optical link to obtain range, Doppler, and signal intensity estimates. These may, in turn, be used to complement or extend the capabilities of current radio science. In this paper we illustrate the achievable parameter estimation errors in estimating range, Doppler,...
The Gravity Recovery and Interior Laboratory (GRAIL) mission to the Moon utilized an integrated scientific measurement system comprised of flight, ground, mission, and data system elements in order to meet the end-to-end performance required to achieve its scientific objectives. Modeling and simulation efforts were carried out early in the mission that influenced and optimized the design, implementation,...
Ultra-stable oscillators (USO) are flown on a variety of different science missions to provide stable timing and/or navigation. Typically, their performance is measured at the part in 1013 level before launch and can only be verified in space via measurements that must propagate through, and potentially be degraded by, the Earth's atmosphere. To date, two missions are able to demonstrate USO performance...
The BepiColombo mission to Mercury has Radio Science objectives that explore planetary gravity and interior structure as well as tests of aspects of the general theory of relativity. Both classes of science objectives rely on high precision Doppler and ranging at dual wavelengths, X-band and Ka-band. In particular, the relativistic tests require ranging between a ground station and the spacecraft...
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