06/16/2016
A month after deployment of the STMSat-1[1] CubeSat from the International
Space Station (ISS), prospects are dimming that the little spacecraft will ever
be heard from. Outside of a weak signal that could have been STMSat-1, nothing
has been received from the little CubeSat - built by students at St Thomas More
Cathedral School in Arlington, Virginia - since it was placed into orbit on May
16. STMSat-1 Education Manager Emily Stocker said that NASA engineer Joe
Pellegrino, who is STMSat-1's mission manager, addressed an assembly at the
school on June 14.
"The assembly we held was specifically to update the students on the status [of
STMSat-1] before they leave for summer vacation," Stocker told ARRL. "The
feeling at the school is still hopeful, but cautiously so, as we have not yet
heard from it." STMSat-1 is supposed to transmit on 437.800 MHz FM and send
slow-scan television (SSTV) pictures back to Earth.
"From the beginning, our mission was to inspire grade-school students - and
anyone else - to pursue STEM careers and pique that interest," Stocker said.
"We have accomplished that mission. While a [SSTV] picture would be nice, that
is simply the icing on the cake."
When a signal from STMSat-1 failed to show up after the CubeSat's release into
orbit, some speculation centered on a malfunction of the antenna deployment
mechanism, which called for a heated blade to burn through fishing line
securing the antennas. Stocker said that, according to the antenna
manufacturer, the antennas should have deployed by now, regardless of the
mechanism, since the fishing line would already have disintegrated due to the
harsh conditions in space.
In his presentation[2] to the students, Pellegrino stressed that space missions
are challenging. He pointed out that the environment of space is very extreme,
and that it's "very difficult to build machines that work in this environment."
"Only half of the CubeSats deployed into space work," he noted. "NASA is a
large organization, with thousands of smart people, and their spacecraft still
fail sometimes." As an example, he recalled the October 2014 Antares launch
failure, in which a couple of CubeSats built by university students were lost.
STMSat-1 was rebooted from the ground on May 24 in an effort to turn on its
transmitter. NASA's 21-meter dish at the Morehead State University Space
Science in Kentucky has continued to scan multiple frequencies for the
spacecraft's signal.
Stocker said in late May that Morehead University "picked up something within
our frequency range," but that it was unclear if the signal came from the
school's CubeSat or from another one deployed from the ISS at the same time as
STMSat-1. JA0CAW posted a tweet reporting a signal heard on 437.800 MHz at 1225
UTC on May 25.
Pupils at the school built STMSat-1 during a 4-year-long project, and the
satellite was launched to the ISS last December. St Thomas More pupils will
continue to track the altitude of the spacecraft on a daily basis to determine
when it will re-enter Earth's atmosphere. In the meantime, they will perform a
cause-and-effect analysis using a fishbone diagram, which Pellegrino explained
during his visit to the school.
Stocker said students were encouraged to think about the fishbone diagram over
the summer as well as to track the altitude of STMSat-1 to accurately predict
when to watch for its re-entry into Earth's atmosphere. When school resumes in
the fall, "we will collect all thoughts about the fishbone diagram and do what
rocket scientists do while we analyze the results and share that with the
community," she added. She invited all STMSat-1 Remote Mission Operating
Centers (RMOCs) to send in fishbone diagrams.
The satellite is the first to be designed and built by grade schoolers, who
have been supported along the way by NASA technical advisors and local radio
amateurs. NASA's Technology Demonstration Office provided the school with a
mobile "clean room" for the construction and a ground-station antenna.
"The students think it is the coolest thing in the world that this mission ends
as a 'shooting star' - and they plan to make a wish," she said. "They - and we
- knew from the beginning that the mission would only last up to 9 months post
deployment from ISS, so this was not news for them."
[1] http://www.stmsat-1.org/
[2] https://drive.google.com/file/d/0B1wUmAxZJJoMUElNLWQyYktCcHc/view
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