All posts by Michael L Umbricht

I’m the Curator of the historic Ladd Observatory. The Observatory opened in 1891 and is part of the Department of Physics at Brown University. Today it is operated as a working museum where visitors can experience astronomy as it was practiced a century ago. I spend most of my time presenting science outreach and public education programs, demonstrations, and exhibits. I’m also responsible for the historic scientific instrument collection. My primary research interest is late 19th and early 20th century astronomy with a focus on precision timekeeping using mechanical clocks and transit telescopes. Other research includes the early history of wireless and the industrialization of Providence.

Satellite tracking

A Cygnus cargo spacecraft was launched to the International Space Station (ISS) on May 21, 2018. Among the supplies that it carried were nine small educational and commercial satellites know as CubeSats. One of the satellites is named EQUiSat. It was designed and built by Brown Space Engineering (BSE) undergraduate students.

Four of these satellites were released on July 13, 2018 from the ISS by astronauts using a device called the NanoRacks CubeSat Deployer. They were ejected at about 1.5 m/.s (3 mph.) Initially they were spaced about 10 to 50 cm (4 to 20 inches) apart. They quickly moved ahead of the ISS together in a cluster as the distance between them more gradually increased over time. EQUiSat is the second cube from the right.

Deployment of a CubeSat flock
Deployment of a “flock” of four CubeSats from the ISS on July 13, 2018. Credit: NASA

Below are maps showing the ground track of the small satellites as they orbit 400 km (250 miles) above the Earth. Also shown are the paths they take across the sky as they pass above the radio ground station at Ladd Observatory. Traveling at a speed of 27,600 km/h (17,100 mph) it takes only 92 minutes to orbit the Earth.

The first pair of diagrams shows the distance between the “flock” of satellites and the ISS on July 16th. This was the first day that orbital elements were published for the CubeSats. It took 3 days before they were separated from the ISS by enough distance that their position could be measured. They lead the ISS by about 400 km (250 miles. ) But they are too close together to be distinguished from each other and each individual satellite can not yet be tracked accurately enough for long term predictions. The tracking is good enough to calculate when they pass above a ground station during the next day or so.
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EQUiSat 1.0 (and future revisions)

Idea for EQUiSat 2.0: “Hall thruster powered by LiFePO4s – to go to the moon”

―Mckenna Cisler ’20, Brown Space Engineering

It began as a thought experiment for a class in 2011: “Developing a mission plan for a space related project.” On July 13, 2018 that plan became a reality when astronauts aboard the International Space Station (ISS) deployed EQUiSat. Undergraduate students from the Brown Space Engineering (BSE) team had designed and built a “cubesat” which NASA then launched on a cargo supply mission to the ISS in May of 2018. After deployment it started transmitting data from low-earth orbit to an antenna on the roof of Ladd Observatory and another ground station at Sapienza in Rome, Italy. In the words of former team member and class of ’14 astrophysicist Emily Gilbert: “***IT’S ALIVE! IT’S ALIVEEEEE!!!!***

Constructing EQUiSat
Hunter Ray working on EQUiSat in the Brown Space Engineering lab on Dec.10, 2017.

The idea for their mission was to test a new battery technology called lithium iron phosphate (LiFePO4) which had never flown in space.  While all space missions are risky using untested components for an important scientific mission or in an expensive commercial satellite is an unacceptably high risk. The students set out to build an inexpensive testbed to prove this technology. The satellite cost $3,776.61 to build. That price tag doesn’t include the countless hours spent by more than 200 students to design and fabricate the parts of the satellite. NASA agreed to launch the satellite for free. If the results look promising it could lower the cost of future space missions and enable new capabilities.

But the technical requirements of the mission are merely a backdrop for a broader vision. The real goal and larger dream of BSE mechanical engineer Hunter Ray ’18 is “For space to become more affordable and accessible to a community other than astronauts and rocket scientists and to be able to look up at the Moon and see the lights of the first permanent extraplanetary settlement.

Continue reading EQUiSat 1.0 (and future revisions)


On March 2, 2018 a severe storm impacted southeastern New England. The storm was classified as a Nor’easter which is named for the characteristic strong winds from the northeast. During the storm our weather station recorded fifty-five wind gusts greater than 50 miles per hour. The two strongest were 62 mph at 1:48 and again at 1:50 pm.

Average wind speed and highest wind gusts graph.

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“An excellent apparatus”

“Connected with this school is an excellent apparatus, including a telescope, which we understand to be among the largest in the State; this, however. is owned by the Principal, Mr. J. M. Ross.

―”Town of Smithfield.”  Twenty-First Annual Report on Public Schools, January 1866.

The School Committee of the Town of Smithfield submitted a report to the General Assembly of the State of Rhode Island for the school year ending May 1, 1865. One of the challenges conveyed was poor attendance by pupils “… who were suffered to be roaming the streets and fields, when they should have been at school.”

Map of Lonsdale
Map showing the location of the village of Lonsdale in the southeastern portion of Smithfield. From Map of the State of Rhode Island and Providence Plantations by Henry F. Walling, 1855.

The Committee highlights the success of the school at Lonsdale, the only high school in the town at the time. The principal is praised for his work and it is mentioned that he lends his own personal telescope for use by the students. The school is seen as a model that other school districts should emulate.

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The observatory that wasn’t

“The writer of this sketch has been there when the building was thronged with guests; some of them in the upper story enjoying the breezes, and the delightful views far and near; some below were at the billiard or card table; some in the nine-pin alley; some in the saloon; and some in the refectory. The hill itself has utterly disappeared and the neighboring houses have all been either removed or torn down, and all that now remains of this once noted scene of fashion, amusement, gayety and dissipation is this picture of the observatory and of several other buildings,—a picture that was taken near the close of the first third of this century.”

― “Fox Point Observatory.” Publications of the Rhode Island Historical Society, April, 1895.

This is not what I was expecting to find when searching for information on the Fox Point Observatory. It was named for the scenic views of Narragansett Bay, rather than for astronomical viewing which is what I was looking for. The only telescope used here appears to be a spyglass for viewing the sailing ships approaching the port by an observer on the deck, as shown below.

Fox Point Observatory.
“The Observatory” as it looked in the early nineteenth century. By Edward Peckham as reproduced in “A Painter of Old Providence.” The Journal of American History, 1912.

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