From idea to flight - A review of the Mobile Asteroid Surface Scout (MASCOT) development and a comparison to historical fast-paced space programs

Abstract

Now spanning a time frame of already 10 years, the plan to land a European Lander on an asteroid has finally been accomplished. The first idea was established around 2008 in the framework of the European Marco Polo Assessment, studying the possibility to collect a pristine sample of a Near-Earth Asteroid and returning it back to Earth. The lander named MASCOT (Mobile Asteroid Surface Scout) was proposed to be carried by the main spacecraft, to land on the surface and by the ability to relocate to investigate multiple surface locations in order to scout the best possible sampling site. After the discontinuation of the original study, MASCOT received an invitation from JAXA to join-in the Hayabusa2 mission, the direct follow-up of the first asteroid sampler Hayabusa. However, MASCOT was selected at a time (mid 2011) when its conceptual design and scientific payloads had not been fully defined; with the carrier spacecraft already in its critical design phase having most of its interfaces fixed; no heritage to use off-the-shelf bus equipment directly and only 3 years left until a proposed final delivery. The tight schedule, tightly defined envelope, and strict margins policy were challenges during its development at all levels. Nevertheless, Hayabusa2 and MASCOT were launched on December 3rd, 2014, and arrived at their destined target asteroid (162173) Ryugu on June 27, 2018. Finally, MASCOT was separated from its mother spacecraft and successfully landed on October 3rd, 2018, accomplishing the first ever landing of a European spacecraft on the surface of an asteroid. This paper provides a review of the performed MASCOT development process including its verification strategy from the first unit hardware test to the final check-out before launch. In addition, it also provides a historical comparison to former fast-paced programs in space.

Concurrent AIV as a method to hard tailor test- and model philosophies in times of need

“…For a full review of this method and a historical comparison to other fast-paced projects and programs in space showing large similarities to Skunk Works, the 1960s Space Race and Faster Better Cheaper, please refer to [10].…”

The MASCOT separation mechanism

“…1 The lander separation shall be commanded via one redundant channel SR-1. 2 The trajectory of the lander after ejection shall not exceed an ejection cone of ±5 • ( 1 ) SR-1. 3 The lander shall be separated at an altitude of 50-100 m above the asteroid surface SR-1.…”

“…All elements were designed according to ECSS standards for the minimization of misalignment errors and cold welding risk and the total mass of the MSM was < 290 g, including PRM 85 g, HDRM 75 g, UMC 65 g, POM 52 g and harness respectively. The functionality and performance of the MSM has been verified by system level tests (presented in detail in [2]), extensive sub-unit tests (e.g. low temperature or even thermal-vacuum and shock/vibration for the PRM, UMC and POM), as well as in dedicated microgravity campaigns using parabolic flights and drop tower experiments (presented in Sect.…”

“…Launched on December 03, 2014, from the Tanegashima Space Center in Japan, the Japanese space probe Haya-busa2 (HY2), carrying the German-French (DLR/CNES) Lander MASCOT (Mobile Asteroid Surface Scount) [1,2], reached its target asteroid (162173) Ryugu on June 27, 2018 [3]. After arrival, HY2 performed first a global mapping to characterize the asteroids global properties and to gather information for the selection of a suitable landing site for MASCOT based on local geology, thermal constraints and scientific interest.…”

Solar Sails for Planetary Defense & High-Energy Missions

“…GOSSAMER-1 was brought to EQM (Engineering Qualification Model) status in an intense integration and verification campaign (cf. [64] [246]) leading to TRL5 status [65] (according to [66], cf. [67][68][69][70][71] [232]).…”