Month: August 2019

Enlarge / The Space Launch System (SLS) rocket’s liquid oxygen tank structural test article was manufactured and stacked in June 2019 at NASA’s Michoud Assembly Facility in New Orleans. (credit: NASA)

Nearly a decade ago, when Congress directed NASA to build a large rocket based upon space shuttle-era technology called the Space Launch System, the agency also quietly put on the back burner its work to develop in-space refueling technology.

It has long been rumored within aerospace circles that funding for NASA's efforts to develop so-called propellant depots, and the capability to store and transfer cryogenic rocket fuels in orbit, was curbed due to the threat it posed to the SLS rocket and its prime contractor, Boeing.

After all, if smaller, cheaper rockets could launch rocket fuel and stash it in low-Earth orbit for staged missions to the Moon or beyond, why should NASA spend $2 billion a year annually to develop the SLS rocket? Why not just use that money to buy commercial launches, starting with the Delta IV Heavy and later the Falcon Heavy, and build an exploration program around existing capabilities? It would likely be quicker and cheaper.

Enlarge / This Cel-Fi Pro coverage unit is in my downstairs den, receiving LTE signal from the network unit upstairs in my living room. (credit: Jim Salter)

I've spent a lot of time talking about how Wi-Fi works and reviewing various products aimed at fixing Wi-Fi dead spots. But today, in our increasingly need-to-always-connect world, what do you do if you've got an LTE (cellular service) dead spot?

Searching Amazon for cellular signal boosters feels like navigating a minefield. Prices range anywhere from $180 to $1,000 and up, and reviews tend to be all over the place for every device offered. Serendipitously, the owner of www.repeaterstore.com reached out to me while I was dithering, and the site offered to let me test a few of the signal boosters they carry. I described two problem areas to him as fertile grounds for testing—my partial basement floor, and my parents' rural house—and we picked out three products to test.

Two of those products—Cel-Fi Go X ($899), and SureCall Fusion4Home ($499)—are products with outdoor Yagi antennas that should be roof or pole mounted and aimed directly at a nearby cell tower. From the outdoor Yagi, a leg of coax cabling needs to be routed indoors and fed to the signal booster, which then has an output port which connects to an indoor panel antenna via another coax run. Since the LTE signal is pretty poor everywhere in my parents' house, kits like these were their best bet.