Purpose of the flight and payload description
WHATSUP stands for Water Hunting Advanced Terahertz Spectrometer on a Ultra-small Platform and was developed at Nasa's Jet Propulsion Laboratory to address the key question of the origin of Earth's water, and more broadly solar system water, which still remains uncertain.
The spectrometer that will be implemented on ultra-small platforms such as CubeSat and SmallSat, will measure the D/H and 17O/18O isotope distribution of water sublimating from comets and is responsive to the Decadal Survey's goal of deciphering the record in primitive bodies of epochs and processes not obtainable elsewhere. The origin of D:H and oxygen isotope anomalies in meteorites has long been a matter of debate, and WHATSUP observations will provide unique information as to whether isotopic ratio gradients are present in the solar system. This would shed light on the origin of the mass-independent isotopic anomaly, and would moreover reliably provide new isotopic constraints on important reservoirs that might have supplied water to the Earth.
WHATSUP features a low-mass and low-power 500-600 GHz molecular spectrometer capable of remotely measuring water isotopes based on their unique rotational molecular spectra at sub-millimeter wavelengths. The D/H and 17/18O relative abundance of comets will be measured to a precision better than a few percent in a few hours of observation from <15,000 km distance by pointing the spectrometer just above the comet's limbs.
The spectrometer includes a heterodyne sensor that is a direct descendant of the 560 GHz MIRO receivers flying on Rosetta; low mass/power silicon integrated circuits that have been developed and demonstrated as part of previous MATISSE effort (a synthesizer and a Fourier transform spectrometer); and an integrated low-loss waveguide switch for differential radiometric calibration.
The spectrometer's ~18 cm aperture diameter achieves a ~3 mrad beam footprint for remote sensing. The mass and power of the instrument are below 2.0 kg and 5 W, making it ideal for implementation on ultra-small platforms such as CubeSat and SmallSat.
Details of the balloon flight
Balloon launched on: 8/20/2021 at 14:06 utc
Launch site: Scientific Flight Balloon Facility, Fort Sumner, (NM), US
Balloon launched by: Columbia Scientific Balloon Facility (CSBF)
Balloon manufacturer/size/composition: Zero Pressure Balloon
Flight identification number: 712N
End of flight (L for landing time, W for last contact, otherwise termination time): 8/20/2021 at 19:21 utc
Balloon flight duration (F: time at float only, otherwise total flight time in d:days / h:hours or m:minutes - ): 5 h 15 m
Landing site: 10 miles W of Belén, New Mexico