ISAS Small Body Exploration Strategy. Many small bodies are born outside the snow line. These are initially comet-like but can evolve to show a variety of faces. By delivering water and organic compounds, these small bodies may have enabled the habitability of our planet.

Joint ISAS-LPL Workshop on Planetary Science Enabled by Epsilon Class Missions

The Institute of Space and Astronautical Science (ISAS) of the Japan Aerospace Exploration Agency (JAXA) and the Lunar and Planetary Laboratory (LPL) of the University of Arizona will hold the second annual workshop dedicated to planetary science enabled by missions to be led JAXA on November 12 and 13, 2017, at the Michael J. Drake Building (a part of LPL) in Tucson, Arizona. Given the nature of the workshop described below, participation will be limited to the first 50 registrants. 

This workshop will be devoted to discussions of planetary missions that are within the reach of ISAS capability and how to make these missions fruitful for the world-wide planetary science community. ISAS uses two launchers for its space science program, Epsilon for the competitive M-class and H-IIA/II for the strategic L-class. The planned cadence is a launch every other year and three in a decade for each class. Due to resource limitations (launch capability, budget, technology for a key instrument not available in Japan), however, it is not necessarily easy to construct a good planetary mission plan if a team is to be limited to domestic members. Participation from international partners such as the United States may be mandatory in some areas. The workshop is a part of the evaluation by ISAS of whether the M (Epsilon)-class planetary missions are attractive to the international (US) community. 

Three specific topics regarding candidate missions in different phases of development will be subject to discussion among the participants of this workshop:

The DESTINY+ (Demonstration and Experiment of Space Technology for INterplanetary voYage, Phaethon fLyby with reusable probe) mission will fly by asteroid 3200 Phaethon, the parent body of the Geminid meteor shower. During the cruise phase, physical and chemical properties of background dust (interplanetary and interstellar dust particles) will be measured in-situ. In-situ dust measurements will also be tried near Phaethon. The role that dust particles played in transporting organic compound to Earth cannot be ignored. Fully comprehensive compositional analysis of interplanetary and interstellar dust particles have not been given yet. The role of active asteroids (Phaethon is an example of this category of small bodies) in releasing dust particles into the interplanetary space may not be dismissed compared to comets. It is this dust in the context of transport of materials in the solar system that sets the background of the focused M-class mission. The interstellar dust part touches on theme of transport into the proto-solar disk. This mission has completed its Phase-A1 study and been approved at the ISAS level as ready to become a JAXA project (as of August 2017). Discussion at last year’s JAXA-Arizona workshop was very helpful in shaping its science case. This year, in addition to an update based on last year’s discussion, the presentation from the team will introduce a new element added to the mission during Phase A1, followed by open discussion on the boost that this new element will give to planetary science. 

JAXA is studying the SolarPowerSail (SPS) mission to the Jupiter Trojans. The mission candidate is now in Phase A1. While it was originally proposed as a demonstration of solar-sail technology, and while it has multiple science themes to pursue during its cruise towards the outer part of the solar system, the request made by the review committee upon entry into Phase A1 is that the Trojan science theme must be made more compelling for SPS to be considered for the next step in the selection. The Trojan-related mission scenario of SPS is to rendezvous with one of the Jupiter Trojans, to deploy a lander, and to make dedicated in-situ analysis on the surface of a Jupiter Trojan asteroid. Is the science case strong enough? Are the science requirements derived appropriately from the science case? Are the instruments designed according to the science requirements? Are the instruments at a proper level of readiness? Synergy with LUCY (multi-flyby of Jupiter Trojans, selected by NASA as a Discovery mission in March 2017) will also be a point of discussion.

The high cadence of ISAS M-class mission is very attractive for small body science, which would benefit greatly from opportunities to perform flybys of a wide variety of asteroids. In a sense, it may be a game-changer for small body missions. Thus, it would be fruitful to review where the small body science stands in the global landscape of planetary science. At the same time, listing of those charming small bodies whose flyby would move planetary science forward should be rewarding. Here, even though the idea for the forum was triggered by the characteristics of the ISAS M (Epsilon)-class mission, in order not to discourage the idea incubation stage by the severely limited capability of the Epsilon launcher, we do not require the target bodies to be within the reach of Epsilon. The workshop will include a discussion of asteroids suggested by workshop participants as flyby targets. Presentations for this portion of the workshop will be selected based on short abstracts from registered participants. Abstracts are limited to 400 words (not including title or authors).

Deadline for abstract submission is 5 p.m. MST, October 27, 2017 or when registration is full, whichever is earlier.

For further information, please contact Tim Swindle, Tim Swindle's email.

NCTS# 32037-18