Flyaway

ACCESS: USAP
Senior Member
Joined
21 January 2015
Messages
10,603
Reaction score
12,149
DART remains on schedule for launch in July 2021 on a Falcon 9 despite the pandemic, said Elena Adams, mission systems engineer for DART at the Johns Hopkins University Applied Physics Lab, which is managing the mission, during the webinar. The spacecraft bus, with its electric propulsion systems installed, recently arrived at the lab for integration and testing.

 
Was Clementine 2 supposed to do something similar with a Brilliant Pebbles derived impactor?

I don't think so. I think Clementine 2 was supposed to be pretty much like Clementine, but going to an asteroid instead of the Moon. (Clementine left the Moon's orbit headed for an asteroid, but a programming error resulted in loss of the spacecraft. I was in the command center outside Washington, DC--a facility called "The Bat Cave"--when it left lunar orbit.)

My institution did a short study on what Clementine 2 could do. I'll have to see if I can find a copy of that report. That was long before I started working there. Our point of contact for that study was the Clementine program manager Stew Nozette. Nozette is currently in federal prison for offering to sell classified information to a foreign government. His arrest wasn't exactly surprising to anybody who ever encountered him. He was a sleazebag.

Update: Found it. Here it is:


I think that although this is about lessons learned from the Clementine mission, the point was to identify things that Clementine 2 could do. I'm pretty sure my co-worker has a report that describes Clementine 2. I'll have to ask him about it.
 
The objective seems to have been somewhat distinct from DART - more geology and less asteroid redirection, since Toutatis is 2.5km long and fifty billion tonnes.

OTOH, the DART target is a 160m 4 million tonne ish moonlet, so dunno whether they expect a bit more movement. Is the lidar that good?
 
They expect to reduce the moonlet's orbital period by 10 minutes, enough to be observed from Earth.
Ah, right, the million-tonne moonlet's orbital speed isn't going to be very high, since it orbits a body with a miniscule escape velocity at a few km every few hours. So a 6.6km/s range <tonne range object could potentially deliver a goodly kick, resulting in a substantial orbit change.

 
Last edited:
My coworker pulled his Clementine files for me. A huge amount of materials, a stack that is probably about 18 inches tall sitting on his desk. Lots of stuff on Clementine. I have to look in there for Clementine II, but they quickly pivoted to this proposal, Oracle. I think that Oracle is basically Clementine II. I'll look through it, but as you can see from the cover, it was a mission to a comet.
 

Attachments

  • 221690091_10221217676738727_4425786705302446490_n.jpg
    221690091_10221217676738727_4425786705302446490_n.jpg
    79.8 KB · Views: 9
  • 218389384_10221217677218739_6047990552732138507_n.jpg
    218389384_10221217677218739_6047990552732138507_n.jpg
    40.2 KB · Views: 7
I went through my coworker's Clementine file. I was wrong, it's only a foot thick, not 18 inches. Unfortunately, it's all Clementine stuff, plus the ORACLE proposal. (The file does include quite a bit of technical detail on the spacecraft and its systems.) I did not find any Clementine II material in there, although I think that we have something on Clementine II somewhere. I'll keep looking.


Update: All I found was a report we did on lessons learned from the Clementine mission. I don't know the origins of this study, but I think it was tied to Clementine II, as in the project team wanted to fly Clementine II, there were various people who questioned whether this was a good idea, and so they asked my organization (long before I worked there) to look at the issue. But rather than asking for a review of Clementine II, they wanted to know what was learned from doing a project like that. It is possible that all of this was done in order to kill Clementine II and prevent it from happening, but I don't know if that's true. Clearly the project team wanted to keep building more stuff.
 

Attachments

  • 218393645_10221232726154953_4068447684627761351_n.jpg
    218393645_10221232726154953_4068447684627761351_n.jpg
    81.1 KB · Views: 7
  • Lessons Learned from the Clementine Mission, 1997.pdf
    245.7 KB · Views: 2
  • Letter, On the NASA,SDIO Clementine Moon,Asteroid Mission.pdf
    47.8 KB · Views: 2
Last edited:
Thinking about this a bit more, my guess is that the Clementine team was pursuing a two-track approach after they flew Clementine. One track was to pitch Clementine II as a DoD mission based on the dubious claim that it would test interceptor technology. This was done around 1992-1997 and they apparently got no traction for that. It's not that surprising, because by the 1990s, missile defense was focused on ground-based interception, not space-based. So there was no reason to fly such a mission.

By 1994, they were pitching ORACLE to NASA. I'm going to be lazy and not read the ORACLE proposal, but my quick skim was that they were essentially proposing the same spacecraft as CLEMENTINE, but to a different target. And I'm going to assume that ORACLE was the same as Clementine II without the impactors. But they got no traction with NASA either. So by late in the 1990s, they gave up and the team split and went to other things.
 
DART Gets Its CubeSat Companion, Its Last Major Piece

It took the team around an hour to get the box precisely aligned and screw in the final bolt. But by 10 a.m. on Wednesday, Sept. 8, LICIACube was fully integrated, putting into place the last major piece of the spacecraft and culminating months of environmental tests and analyses as each of DART’s components have been mounted.

Contributed by the Italian Space Agency (ASI) and designed, built and operated by the Italian aerospace engineering company Argotec, LICIACube (pronounced LEE-cha-cube) has the important task of watching DART’s final maneuver – a deliberate crash into an asteroid – and its effects.

“Seeing LICIACube installed on DART was exciting because this mission breaks new ground for ASI and the whole Italian space sector,” said Simone Pirrotta, LICIACube Project Manager for ASI. “It will be the first Italian satellite ever to operate in deep space, requiring the training of a large and motivated national team that is now well qualified to tackle similar challenges in the future.”

The mission objective of DART, which was designed, built and is managed by APL, is to determine whether flying a spacecraft into a small solar system body at speeds of about 15,000 miles per hour could be a reliable technique to deflect an asteroid if such a hazard were ever discovered to be on a collision course with Earth.

The mission’s target is a binary asteroid system — Didymos and its small moonlet asteroid Dimorphos. Neither poses a threat to Earth, but their orbit around the Sun swings them close enough to the planet that ground-based telescopes can observe the aftermath of DART’s collision and calculate how effective it was at changing Dimorphos’ path. Those observations, along with DART’s main imager DRACO—the Didymos Reconnaissance and Asteroid Camera for Optical navigation—will ultimately achieve all of DART’s mission objectives. But the images LICIACube captures will significantly enhance the mission’s overall knowledge return, and hope to provide spectacular testament of its success.

LICIACube is equipped with two optical cameras, dubbed LUKE (LICIACube Unit Key Explorer) and LEIA (LICIACube Explorer Imaging for Asteroid). These will capture scientific data and inform the microsatellite’s autonomous system by finding and tracking the asteroid throughout the encounter.

The CubeSat will deploy 10 days prior to DART’s kinetic impact, kicking out of its spring-loaded box at roughly 2.5 miles per hour. LICIACube will then use its onboard propulsion system to alter its trajectory, offsetting itself so it flies past Dimorphos around three minutes after the DART impact. That delay will give LICIACube the opportunity to capture images of the impact’s effects, including the resultant plume of ejecta and possibly the newly-formed impact crater, as well as the backside hemispheres of both Didymos and Dimorphos that DART will not see.

“For a first mission, it’s really something,” said Andy Cheng, an APL planetary scientist and lead investigator of DART. “Without LICIACube, there would be no observation of the ejecta cloud,” which can reveal details about how much material was kicked out, how fast it was ejected and in what direction, Cheng said. That information will help further characterize the momentum exchange between DART and the asteroid and, thus, how effective the kinetic impact was at deflecting Dimorphos.

“We are eager to obtain these unique in situ images," said Elisabetta Dotto, LICIACube scientific coordinator from the National Institute for Astrophysics in Rome. “It will be so exciting to study, for the first time, the nature and structure of such weird objects as binary [near-Earth asteroids].”

In the last week of September, DART departed for Vandenberg Space Force Base near Lompoc, California, where it is scheduled to launch in late November on a SpaceX Falcon 9 rocket. The spacecraft will set course to collide with Dimorphos in fall 2022, which will change the period of the moonlet’s 12-hour orbit around the main body by several minutes. Scientists will use ground-based telescopes to determine the exact change in the orbital period. LICIACube’s X-band communication system will transmit the spacecraft’s imagery back to Earth over the months following DART’s collision.

Redirecting Asteroids podcast

Tom Statler describes a NASA planetary defense mission to test technologies and capabilities for redirecting asteroids.
 
Processing of NASA’s Double Asteroid Redirection Test (DART) spacecraft continues as the spacecraft was transported from the Astrotech Space Operations Facility to the SpaceX Payload Processing Facility (PPF), part of Space Launch Complex 4 at Vandenberg Space Force Base in California, on Oct. 26. The following day, the spacecraft was removed from its container and technicians performed an aliveness test to confirm DART was in good health.
 
I meant to post these last week:



 
An intercept/fly-by trajectory is faster than a Rosetta type matching trajectory a gravity-tractor would need---correct?
 
Just two weeks after launching from Vandenberg Space Force Base in California, NASA’s Double Asteroid Redirection Test (DART) spacecraft has opened its “eye” and returned its first images from space — a major operational milestone for the spacecraft and DART team.
 
Let’s wait and see what happens when DART hits the Asteroid, it could either work and nudge it out of it’s current orbit or it could fail. I really wish that it is going to work, fingers and toes are going to be crossed that it is the former.
 

Similar threads

Back
Top Bottom