Paul Spudis does an excellent job describing why Express-AM4 should be saved, and then makes a comparison to how things should proceed for Lunar Exploration.
Read here:
Can We Repurpose Space Assets?
AM4 is still up, although reports from Russia show it scheduled to be de-orbited on the 25th.
Astrogator Mike has worked a lot recently on a re-purposing plan for the Express-AM4 spacecraft, and is quoted extensively in this article.
Don’t splash the bird!
Russians to decide on Polar Broadband Plan
This could be a great mission for science, and involved some decent Earth-orbiting astrogation. Stay tuned for more details of this orbit once we hear the fate of the bird. Don’t miss the associated video here:
Lawrence Livermore National Laboratory (LLNL) and the Air Force Joint Space Operations Center (JSpOC) came up with a new approach to predicting re-entry while trying to track Phobos-Grunt. Article here:
A New Approach to Predicting Re-Entry
Basically their approach was to take a supercomputer and give it access to the best real-time tracking available. Sounds like their results were pretty good.
(Follow-up from Dan Adamo)
It seems Nature has supplied a timely footnote for my 2011 AG5 risk corridor analysis. Attached are heliocentric and geocentric plots spanning NEO 2012 DA14’s close Earth approach on 15 Feb 2013. Recent Horizons prediction data (reference ephemeris JPL#15) for that event appear in the following table.
The following is from Dan Adamo, guest astrogator and a former Flight Dynamics Officer at JSC. Dan runs a mail list called the ATIG (Astrodynamics Technical Interchange Group). Last year he graciously allowed me(Mike) to be a part of the group, and since then I get interesting articles from him every month or so. This month, Dan sent the following, which I thought was a great topic for the guild.
Dan Adamo
Earth Risk Corridor Computations for 2011 AG5 on 5 February 2040
Introduction
The near-Earth object (NEO) designated 2011 AG5 is currently associated with a relatively high linearized Earth impact probability of 0.001557 (odds of 1-in-642.3) during its predicted 5 February 2040 close approach to Earth. This probability appears in Table 1 (reference the P_i/p column), together with data pertaining to other near-term 2011 AG5 planetary approaches closer than 0.1 AU (15 million km). These predictions are obtained from JPL’s Horizons on-line solar system data and ephemeris computation service* using the current JPL#45 orbit solution for 2011 AG5. Note that coordinate time (CT) is a uniform time scale void of leap seconds and used as the fundamental ephemeris argument by Horizons. To a precision of ±0.002 s, CT is related to atomic time (TAI) by CT = TAI + 32.184 s.
