Mini-satellites: An Astronomical Revolution
(Less is More [LIM])

Start
The following arguments motivate us to consider a program of astronomical satellites with mass budget of less than one hundred kg.

1. Technological advances in miniaturization make it possible to obtain powerful capabilities in space but with modest to moderate mass requirements. We note here that, by many accounts, Israel is the leader in this area.
2. Increase in access to space given the entry of several countries (e.g. China, India) and commercial players in the US and Russia. The increasing number of launchers has led to a decrease in launch costs.
3. Ground stations can be built at modest cost ($200K), thanks to advances in receiver technology and telescope costs (12-m category) -- the latter enabled by radio astronomers in their quest for SKA (e.g. dishes for MEERKAT, ASKAP and ATA).

Next, as astronomy facility missions pursued by the big players become larger (e.g. JWST, JDEM, Darwin, Spica), a new opportunity opens up for nimble players who can take advantage by focusing on high yield missions aimed at answering one or few questions.

Apart for the cutting edge science goals we strongly believe that training future generation of students in "nimble" space astronomy as well as flying "modest" space missions will fulfill a key goal of our institutions (elite manpower training) and in the longer goal give our institutions a significant advantage in gaining leveraged access to other missions (ground or space).

Our default plan is a satellite in the mass range 50 to 100 kg and which can undertake high impact science for even one goal. However, we are open to ideas involving multiple (and unrelated) space craft (e.g. good for sky coverage) or a loosely bound cluster (e.g. low frequency radio astronomy). The key is to fly a mission every three years using as much as possible the same line of systems and sub-systems.

We are not the only ones thinking about this approach. In the Goldin era there was a push for UNEX (University Explorer's) and the result was CHIPSAT. The trials and tribulations of this project should give us some pause as we dream on. Canada's MOST mission a 65-kg satellite designed to study astro-seismology took advantage of "new Canadian attitude control technology" -- as is also the case for Austria's BRITE, a 10 kg photometry satellite (but not yet launched). FInally, we have (in phase B) Brazil's MIRAX mission.

A question that can and has been raised is
"How can a 100-kg satellite beat larger missions (especially in traditional bands of observations)?"
This is an excellent question and indeed answering it clearly is an essential part of the clarifying the vision of this effort. There are several potential strategies:

1. New Areas. Choose an area of astronomy that has not received the attention of larger missions (e.g. low frequency radio astronomy)
2. Narrow Focus. Choose a very specific project that requires considerable allocation of time (e.g. stellar seismology; this is the basis of MOST, COROT and TUGSAT-1).
3. Single Objects. Monitor the Galactic center/bulge (e.g. MIRAX) or our neighbours (e.g. SMC, LMC or M31).
4. Low Surface Brightness. Large collecting area is not needed for projects focused on surface brightness (CHIPSAT).
5. Leverage. Obtain a very high leverage by coupling the space mission to another project with some unique returns (e.g. PTF, ASKAP) and large projects (e.g. LSST, LIGO).

Our initial plan has been made with some thought: a discussion amongst the scientists to define the vision (without worrying about agencies or institutional affiliations or institutional permissions). During this "dream" phase we should brain storm whilst taking a very critical view of the larger landscape and identify weaknesess in the camps of Goliaths. We need to consult experienced engineers at NASA centers (JPL, Ames), ISA, ISRO and CSA and appreciate how advances in various technologies can be incorporated into our vision. We should also learn from the experiences of past missions (particularly CHIPSAT, MOST). Only once we have a well defined vision will we apporach the agencies.

The document is organized as follows:

• Potential Projects
• Other Interesting Projects
• Potential Vendors
• Other Aspiring Countries
• A Critical assessment of returns of small satellites